I/O interface devices or units support communication between a computer system and a variety of I/O devices. Examples of I/O devices include terminal devices, such as video display devices or speakers, and user input devices, such as a keyboards, mice, keypads, touch pads, trackballs, buttons, light pens, or other pointing devices. Other examples of I/O devices are storage devices, such as disk drives or direct access storage devices, which are typically rotating magnetic disk drive storage devices, although they may be other storage devices, including arrays of disk drives configured to appear as a single large storage device to a host computer. Further examples of I/O devices are various other input/output devices, such as printers or fax machines. Yet other examples of I/O devices are network interface devices that provide one or more communications paths from a computer system to other digital devices and computer systems. The communication paths may include one or more networks, e.g., an Ethernet network.
I/O interface devices or units are also known as I/O processors or I/O adapters. An I/O interface device may be integrated into a system-on-a-chip or provided on a mother board of a computer system. In addition, an I/O interface device may be manufactured as a standalone circuit board having a connector for installing the device into a slot or socket (e.g., a complementary connector) on a mother board of a computer system.